Bodong Chen, Monica Resendes
University of Toronto
LAK14, March 28, 2014
| Categories | Examples |
|---|---|
| Questioning | “Why leaves change color?” |
| Theorizing | “I think it's because of the cold weather.” |
| Obtaining evidence | “Let's put a tree in our classroom to test that theory.” |
| Working with evidence | “I read that chlorophyll keeps leaves green. Maybe it goes into the tree to keep warm for the winter.” |
| Synthesis & analogies | “Put our knowledge together: Because the sap can't get to the leaf, the chlorophyll dies and the leaf change color.” |
| Supporting discussion | “I like this idea.” “We should not talk about irrelevant stuff.” |
(Chuy et al., 2011)
Resendes, Chuy, Chen, Bereiter, & Scardamalia, 2011, CSCL
# Function for comparing LsA measures
CompareLsAMeasures(measure="freq", ncodes, lag=1, adjacent=TRUE)
| Grades | Units | Number of notes |
|---|---|---|
| Grade 1 | Water | 298 |
| Grade 2 | Trees | 117 |
| Grade 3 | Fungus | 193 |
| Grade 4 | Rocks and Minerals | 262 |
| Grade 5/6 | Astronomy | 231 |
Content analysis (done prior to the present study)
| Grades | # of notes | # of threads | # Productive | # Improvable |
|---|---|---|---|---|
| Grade 1 | 298 | 12 | 9 | 3 |
| Grade 2 | 117 | 6 | 4 | 2 |
| Grade 3 | 193 | 8 | 5 | 3 |
| Grade 4 | 262 | 11 | 6 | 5 |
| Grade 5/6 | 231 | 13 | 7 | 6 |
Between productive and improvable dialogues, no significant difference was found on basic contribution measures.
| Measures | Productive | Improvable |
|---|---|---|
| # of units | 20.90 (9.15) | 23.84 (12.44) |
| # of units–merged | 14.23 (7.58) | 15.74 (9.68) |
| Questioning | 4.77 (3.33) | 5.53 (3.47) |
| Theorizing | 9.19 (5.49) | 11.89 (6.34) |
| Obtaining evidence | 2.42 (1.50) | 1.89 (2.08) |
| Working with evidence | 1.32 (2.06) | 0.84 (1.64) |
| Synthesizing and Analogies | 0.42 (0.92) | 0.58 (1.02) |
| Supporting discussion | 2.77 (3.04) | 3.11 (2.66) |
# The first 10 lines of the data
# Each line represent a note
head(dfc, 10)
grade thread noteid coding
1 4 FORMING ROCKS 1 Q
2 4 FORMING ROCKS 4 Q
3 4 FORMING ROCKS 6 Q
4 4 FORMING ROCKS 7 T
5 4 FORMING ROCKS 9 T
6 4 FORMING ROCKS 12 WE
7 4 FORMING ROCKS 13 T
8 4 FORMING ROCKS 15 S
9 4 FORMING ROCKS 16 T
10 4 FORMING ROCKS 18 Q
# Subset notes of ONE thread
dfc_sub <- subset(dfc, thread == t)
# Compute trasitional matrix for this thread
v_m <- GetTransactionalMatrix(dfc_sub$coding, ncodes, lag, adjacent)
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 2 2 1 1 0 1
[2,] 2 3 2 5 0 4
[3,] 0 2 0 2 0 0
[4,] 2 4 0 2 0 2
[5,] 0 0 0 0 0 0
[6,] 0 5 1 0 0 2
# Compute adjusted residuals
GetAdjustedResiduals(v_m, adjacent)
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1.03 -0.42 0.55 -0.55 -1 -0.26
[2,] -0.42 -1.75 0.63 1.08 -1 0.94
[3,] -0.90 0.63 -0.65 1.40 -1 -0.97
[4,] 0.44 0.33 -1.12 -0.19 -1 0.21
[5,] -1.00 -1.00 -1.00 -1.00 -1 -1.00
[6,] -1.34 1.76 0.40 -1.67 -1 0.59
# Compute Yule's Q
GetYulesQ(v_m, ncodes)
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 0.55 -0.19 0.32 -0.30 -1 -0.23
[2,] -0.06 -0.56 0.32 0.37 -1 0.23
[3,] -1.00 0.32 -1.00 0.61 -1 -1.00
[4,] 0.32 0.12 -1.00 -0.08 -1 0.00
[5,] -1.00 -1.00 -1.00 -1.00 -1 -1.00
[6,] -1.00 0.60 0.24 -1.00 -1 0.18
# Flatten Yule's Q Matrix into a vector
as.vector(t(v_m))
# Combine vectors of all 50 threads
# resulting in a 50x38 table
dft_lag_measures[1:6, 1:6]
type count X1_1 X2_1 X3_1 X4_1 ...
1 e 45 1.03 -0.42 0.55 -0.55
2 e 10 -0.79 1.29 -0.86 -1.00
3 i 9 -0.38 1.50 -0.57 -1.00
4 e 15 -2.35 2.84 -1.00 -1.00
5 i 35 -0.28 -1.46 1.72 -1.00
6 e 11 -0.33 -0.49 0.14 -1.00
...
# t-test: transition 1 -> 1 (questioning)
t.test(X1_1 ~ type, data=dft_lag_measures)
Significance tests
CompareLsAMeasures(measure="yule", ncodes, lag=1, adjacent=TRUE)
| Next Move | ||||||
|---|---|---|---|---|---|---|
| Current Move | 1 | 2 | 3 | 4 | 5 | 6 |
| 1. Questioning | - | |||||
| 2. Theorizing | - | |||||
| 3. Obtaining Evidence | ||||||
| 4. Working with Evidence | ||||||
| 5. Syntheses & Analogies | ||||||
| 6. Supporting Discussion | - | - |
+: significantly more frequent in effective dialogues; -: vice versa
In addition